Flexible maple sap collecting tubing



1966 R. M. LAMB 3,226,883

FLEXIBLE MAPLE SAP COLLECTING TUBING Filed May 12, 1964 V 2 Sheets-Sheet 1 INVENTOR.

R.M. LAMB Jan. 4, 1966 R. M. LAMB 3,226,883

FLEXIBLE MAPLE SAP COLLECTING TUBING Filed May 12, 1964 2 Sheets-Sheet 2 45 FIG. 5

INVENTOR.

R.M. LAMB BY United States Patent ()7 This application a continuation in part of" my copending application Serial Number 283,317 filed May 27,

1963: (now abandoned) This invention relate to the collection of maple sap in the sap harvesting and in particu:

lar to the tubing used for main orlateral lines in systems employing flexible tubes for conveying the sapcollected from maple trees. Normally, a spile is set in a taphole of the tree and a downwardly extending flexible tube,

commonly termed drop lines," is connected fluid tight with the spile for flow of sap therefrom by gravity. The drop line is connected fluid tight with the lateral line which in turn is connected fiuid 'tight with the main line.

For a detail description of systems of this general type, reference is made to a publication of the US. Department of Agriculture, Agriculture Research Service, entitled The Use of Plastic Tubing for Collecting and Trans- Porting Maple S ri y QtQ-W l s an loy sipple. identified as ARS' 73-35. A similar system is also disclosed in my copending application Serial Number 236,- 988, filed November 13,1962, now, Patent No. 3,156,069.

The main or lateral lines are transversely extending, flexible imperforate tubes, generally supported directly on the terrain, inclined so that the sap flows by gravity through them to storage tanks in the field or in the evaporator house. Frequently the tubes lie on snow. Under certain weather conditions, warm sap which comes directly from the trees will cause a tube to melt its way into the snow. Ifa cold period follows suificient to freeze a plug of sap in the portion of the tube which is under snow, subsequent sunlight, or warmer ambient temperatur'e, does not have opportunity to melt the plug. It is then necessary manually to lift the tubes from the snow in order to reestablish sap flow. This task is time cansuming, and often results in a decreased sap yield due to the additional time required to free the tubes and permit the plug or plugs tothaw. t

The present invention mitigates the tendency of such tubing to melt its way into the snow.

In general, according to the invention, the transversely extending, flexible, imperforate tubes which may lie on snow are provided with outwardly projecting fins extending lengthwise of the tubes. These fins do not warm to the extent the tube wall is warmed by the warm sap flowing through the tube. As a result the fins support the tube on or near the surface of the snow, even if the snow melts from directly below the tube. i

For a detail description of the invention, reference is made to the accompanying drawing in which:

FIGURE 1 is a section through such a transversely extending tube showing it in use position lying on the snow;

FIGURE 2 is a section similar to FIGURE 1 illustrating a variation; 7

FIGURE 3 is a section of another embodiment of the tube;

FIGURE 4 is a section of another embodiment; and

FIGURE 5 illustrates schematically a system employing the transversely extending tubes of the invention.

Referring to the drawing, the flexible, imperforate tube 11, made of a plastic material of known kind, is provided with an integral outwardly projecting fin 12 and a similar fin 13. The fins are equally spaced from each other circumferentially of the tube and extend lengthwise. The tube is shown in use lying on snow 15 inclined for gravity flow of the sap, A pocket- 16' resulting from melted'sno-w is illustrated.

The tube may be laid atra-ndomon the snow. In this event certain spans will lie with their fins positioned vertically. Adjacent sections with the fins lying horizontally hold the vertical fin spans on the snow. However, even me long span witha fin directed downward the tubing stays up admirably well. It-is probable,since the fin does not warm as easily as the wall, the plastic material from which the tube made being quite" a good heat insulator, that the fin rideson the snow even wherea pocket is formed by melting snow. Such is illustrated in FIGURE 2 in which only. one fin18 isshown.

The tube shown in FIGURE 3 is like that of FIGURE 1 except that it is provided with three equally spaced fins 20, 21 and 22. l

1 Thetube illustrated in FIGURE 4 is also similar, except being provided with four fins 25 26, 27 and 28.

Referring to FIGURE 5, twornaple trees 30 and 3-1 are shown provided with spiles 32 and 33, each set in a taphole of a tr'ee. The spiles and vent tubes 34 and 35 are similar to the spile and vent tube shown in FIGURE 5 of my copending application, Serial Number 236,988; A flexib fi, downwardly extending, fluid tight drop-line tube 3 6, is connected fluid tight to the spile 32 so that. sap flowsfromthe spile by gravity. A similar drop-line tube 3.7 isc nnec e to h le The lateral line 11 extends transversely and lies inclined, It is connected fluid tight to tube 36 with a conventional T-connector 38. A main line 11' also extends transversely and lies inclined. It is connected fluid tight to the lateral line 11 with a T-connector 39, and fluid tight to tube 37 with a T-connector 40.

Due to the inclinations of the lateral and main lines the sap flows by gravity to the storage tank, shown schematically at 45.

r The tubes, such as 11 and 11' in FIGURE 5 of the present invention, vary in size. They should be large enough to carry the sap and yet permit tree sap gases which evolve from the sap to move opposite to the sap flow and escape though the vents. The main lines 11 are normally larger than the drop-line tubes and the lateral lines. In case tubing much larger than required is used, larger plugs of frozen sap may occur, unduly lengthening the time required for thawing sufficiently to allow the flow to commence. Also the larger tubing costs more and is more difficult to handle.

For the smaller size lateral lines, an internal diameter of .295 to .310 inch is ideal, the latter size representing 1 the standard tube. The larger main lines may require quite a large size, depending on the number of spiles supplying the tube, /2 to 1 inch internal diameter being usual.

The tubes are extruded from a flexible plastic material. Polyvinyl chloride is preferred for the smaller tubes and polyethylene for the larger tubes. The polyethylene is less expensive, but not as flexible. However, since the main lines take a more straight run, the greater flexibility of the polyvinyl chloride is not necessary. The flexibility should be'such that the tubescan be coiled for storage and not collapse. Such handling is essential since they are removed from the field, cleaned and stored for future use after each sap harvesting season.

The tube color is preferably a light violet, transparent to the ultraviolet rays in sunlight. The ultraviolet rays thus penetrate into the tube and aid in the control of microorganism growth in the sap.

Other thermoplastic materials may be used. Of the vinyl compounds, such plastics as polyvinyl dichloride and polyvinylidene fluoride may be substitued. Other suitable plastics are polytetrafluore-thylene, polychloro- Batented J am. i, 1966 trifluorethylene, cellulose acetate, cellulose butyrate, and chlorinated polyethers.

The dimensions of the fins on the tube are not critical but it is recommended that the fins project outwardly at least one half the diameter of the tube.

The desired plasticity and color are obtained by use of plasticizers and pigments in the thermoplastic materials by known procedure. Also compatible thermoplastic materials may be combined.

I claim:

1. In a maple sap collecting system, a transversely extending, flexible, imperforate tube lying inclined on the snow for.conveying maple sap by gravity flow, from a spile set in a taphole of a maple tree to a storage tank, said tube having a plurality of outwardly extending fins integral with the tube and equally spaced circumferentially thereof to support the tube on the snow and thereby mitigate the tendency of the tube to melt its way into the snow upon the flow of warm sap therethrough.

2. In a maple sap collecting system, a transversely extending, flexible, imperforate tube lying inclined on the snow for conveying maple sap by gravity flow from a spile set in a taphole of a maple tree to a storage tank, said tube having two outwardly extending fins integral with the tube and equally spaced circumferentially thereof to support the tube on the snow and thereby mitigate the tendency of the tube to melt its way into the snow upon the flow of warm sap therethrough.

3. In a maple sap collecting system comprising a spile set in a taphole of a maple tree and a flexible, downwardly extending fluid t-ig-ht tube connected with the spile for flow of sap therefrom by gravity, a transversely extending, flexible, imperforate tube lying inclined on the snow and connected with the downwardly extending tube for flow of the sap by gravity to a storage tank, said transversely extending tube having a plurality of outwardly extending fins integral with the tube and equally spaced circumferentially thereof to support the tube on the snow and thereby mitigate the tendency of the tube to melt its way into the snow upon the flow of warm sap therethrough.

4. In a maple sap collecting system comprising a spile set in a taphole of a maple tree and a flexible, downwardly extending fluid tight tube connected with the spile for flow of sap therefrom by gravity, a transversely extending, flexible, imperforate tube lying inclined on the snow and connected with the downwardly extending tube for flow of the sap by gravity to a storage tank, said transversely extending tube having two outwardly extending fins integral with the tube and equally spaced circumferentially thereof to support the tube on the snow and thereby mitigate the tendency of the tube to melt its way int-o the snow upon the flow of warm sap therethrough.

References Cited by the Examiner UNITED STATES PATENTS 2,750,232 6/1956 Szantay et a]. 3,057,115 10/1962 Bilanin 4752 ABRAHAM G. STONE, Primary Examiner.

T. GRAHAM CRAVER, Examiner.

ROBERT E. BAGWILL, Assistant Examiner. 

2. IN A MAPLE SAP COLLECTING SYSTEM, A TRANSVERSELY EXTENDING, FLEXIBLE, IMPERFORATE TUBE LYING INCLINED ON THE SNOW FOR CONVEYING MAPLE SAP BY GRAVITY FLOW FROM A SPILE SET IN A TAPHOLE OF A MAPLE TREE TO A STORAGE TANK, SAID TUBE HAVING TWO OUTWARDLY EXTENDING FINS INTEGRAL WITH THE TUBE AND EQUALLY SPACED CIRCUMFERENTIALLY THEREOF TO SUPPORT THE TUBE ON THE SNOW AND THEREBY MITIGATE THE TENDENCY OF THE TUBE TO MELT ITS WAY INTO THE SNOW UPON THE FLOW OF WARM SAP THERETHROUGH. 